Load-carrying additives and compositions thereof

ABSTRACT

Adducts of alkylphosphorous triamides with alpha, beta-unsaturated carbonyl compounds provide novel sulfur-free load-carrying additives for various organiccompositions, e.g., lubricant oils.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This application is directed to oil-soluble, sulfur-free load-carrying additives comprising novel adducts of phosphorous triamides and alpha, beta unsaturated carbonyl compounds. This application is also directed to organic compositions, e.g., lubricant compositions containing said novel adducts.

2. Description of the Prior Art

The use of phosphorus compounds as load-carrying or antiwear agents in lubricant compositions is known. Also, the use of phosphorus compounds in combination with organic materials is known. For example, U.S. Pat. Nos. 3,115,465 and 3,986,967 disclose the use of phosphorus compounds in combination with hindered phenols or benzotriazole as lube oil additives.

SUMMARY OF THE INVENTION

This application, however, is directed to the discovery of adducts of phosphorus, e.g., hexaalkyl phosphorus triamides and alpha, beta-unsaturated carbonyls, e.g., methyl acrylate as novel compounds and load-carrying additives for various organic media, e.g., oils of lubricating viscosity or greases prepared therefrom.

The application is therefore also directed to lubricant compositions having a major proportion of, for example, a lubricant and a minor load-carrying proportion of the hereindescribed novel adducts.

The novel compounds have the following general structure ##STR1## where n is 0, 1 or 2; q is 1, 2 or 3, with the proviso that the sum of n and q equals 3 and where R and R' are each selected from alkyl of from 1 to about 32 carbon atoms, aryl, aralkyl or alkaryl of 6 to about 30 carbon atoms. R and R' may be alicyclic (C_(m) H_(2m-1)) such as cyclopentyl (C₅ H₉ ⁻) or cyclohexyl (C₆ H₁₁ ⁻) and RR' may be (CH₂)_(m) comprising part of a heterocyclic system such as (--CH₂ ⁻)₄ in pyrolidine or (--CH₂ ⁻)₅ in piperidine. R², R³ and R⁴ may be H, or alkyl of 1 to 32 carbon atoms or aryl, aralkyl, alkaryl of 6 to 30 carbon atoms, and R⁵ may be alkyl, or hetero substituted alkyl of 1 to 30 carbon atoms, aryl, aralkyl or alkaryl of 6 to 30 carbon atoms.

The preferred novel compounds in accordance with this invention have the following general structure ##STR2## where the substituents are as defined above.

The phosphorous triamides useful in this invention have the following general formula:

    (RR'N).sub.3 P

where R and R' are as previously described. They may be obtained commercially or synthesized in any convenient manner known to the art. For example, any secondary amine such as dimethylamine may be reacted in the following manner with a phosphorus halide PX₃ (X may be bromo, chloro or iodo) such as PCl₃ under appropriate reaction conditions to yield the desired triamide:

    6RR'NH+PCl.sub.3 →(RR'N).sub.3 P+3RR'NH.sub.2 Cl.

Any suitable secondary amine, RR'NH, may be used, e.g., diethylamine, N-methylaniline and so on. R and R' are as previously described. The phosphorous triamide is then reacted with a carbonyl-containing compound according to the general procedure below which exemplifies methyl acrylate: ##STR3## The reaction is exothermic with temperatures occasionally exceeding 110° C. General reaction conditions include room temperature to 200° C. and preferably room to 85° C., atmospheric pressure or higher if desired with reaction times ranging from 1 to 6 hours.

The R group in the organophosphorus reactants are hydrocarbyl containing up to 32 carbon atoms, which can be alkyl, aromatic or alkyl-substituted aromatic. The aromatic groups include phenyl, naphthyl and anthryl, and those members substituted with a C₁ -C₁₈ alkyl. Such alkyl groups include methyl, butyl, octyl, decyl, dodecyl, tetradecyl, octadecyl and the like, and it will be understood that the mention of each of these is a disclosure of its attachment to each of the aromatic groups mentioned and the incorporation of the alkylaromatic compound into the various final products contemplated by this invention. Finally, the alkyl group R can also have from 1 to 32 carbon atoms and includes methyl, ethyl, hexyl, nonyl, tetradecyl and octadecyl, eicosyl, pentacosyl, triacontyl and dotriacontyl. Here again, the disclosure of each of these groups is a disclosure of their incorporation in all the various final products of this invention.

Suitable carbonyl compounds include any suitable alpha, beta, unsaturated carbonyls such as methyl acrylate, 2-ethylhexyl acrylate, dimethylaminoethyl methacrylate, stearyl methacrylate, ethyl cinnamate, ethyl crotonate, ethyl maleate, methyl vinyl ketone, etc.

The compounds of this invention are especially effective in lubricant compositions in which the lubricant base is a petroleum product, such as a mineral lubricating oil, a synthetic lubricant fluid or an ester-base oil. Such synthetic fluids include synthetic hydrocarbon oils derived from long chain alkanes or olefin polymers, ester oils obtained from polyhydric alcohols and monocarboxylic acids or monohydric alcohols and polycarboxylic acids. Also the lubricant herein includes greases made from the named classes of lubricant compositions and/or fluids.

The concentration of additive may vary from about 0.05 to about 10% by weight. Optimum performance characteristics are evidenced by lubricants containing from about 0.25% to about 2% by weight of the additives of this invention, and this is the preferred range of concentration.

The following examples are offered as illustrations of the invention.

EXAMPLE 1 Preparation of Tri[1-carbomethoxy-2-tetramethyleneamino ethyl]phosphine ##STR4## To a stirred solution of methyl acrylate (129 g., 1.5 moles) and 100 ml of 2-methoxyethyl ether (diglyme) at room temperature in a 500 ml reaction flask protected from moisture, was added dropwise, 53.2 g. (0.2 moles) of tris[tetramethylene]phosphorous triamide. After the addition and the ensuing exothermic reaction had subsided (temperature rose to 120° C.) the reaction mixture was refluxed for 31/2 hours and then stripped under vacuum. EXAMPLE 2 Preparation of Tri[1-carbomethoxy-2-pentamethyleneamino ethyl]phosphine ##STR5## This compound was prepared as outlined in Example 1 except that tris pentamethylenephosphorous triamide was used. EXAMPLE 3 Preparation of Tri[1-carbomethoxy-2-N,N,diethylaminoethyl]phosphine ##STR6## This was prepared as outlined in Example 1 except that hexaethylphosphorous triamide was used. EXAMPLE 4 Preparation of Tri[1-carbomethoxy-2-N,N,dibutylaminoethyl]phosphine ##STR7## This compound was prepared as outlined in Example 1 except that hexabutylphosphorous triamide was used.

The additives prepared in the above examples were evaluated in the standard 4-Ball Wear Test using 1/2 inch 52100-steel balls at a load of 60 kilograms for 30 minutes under the conditions set forth in the table below. The oil used was an 80/20 mixture of a solvent refined Mid-Continent paraffinic 150/160 second bright mineral oil.

The data in the table clearly establish that the lubricant additives in accordance herewith possess good load-carrying properties.

It is understood that only preferred embodiments have been exemplified, which in no way limit the specification or claims, departure therefrom is within the skill of the art.

                                      TABLE                                        __________________________________________________________________________     4-Ball Wear Scar Diam (mm)                                                     1/2" Balls, 52100 Steel,                                                       60 kg, 30 minutes                                                                                     Conc.                                                                              Temp.                                                                              SPEED (RPM)                                     Ex.                                                                               Additive            Wt. %                                                                              °F.                                                                         500                                                                               1000                                                                              1500                                                                              2000                                   __________________________________________________________________________        None (Base stock                                                                 mineral oil)       100                                                                               Room                                                                               0.50                                                                              0.60                                                                              0.88                                                                              2.34                                                              200 0.60                                                                              1.06                                                                              1.86                                                                              2.23                                                              390 1.0                                                                               1.31                                                                              2.06                                          ##STR8##           1   Room 200 390                                                                       0.40 0.50 0.60                                                                    0.50 0.50 0.50                                                                    0.50 0.50  0.70                                                                   0.50  0.50  0.70                       2                                                                                  ##STR9##           1   Room 200  390                                                                      0.40  0.50  0.80                                                                  0.40  0.50  1.0                                                                   0.50  0.50  0.70                                                                  0.50  0.70  0.80                       3  [(C.sub.2 H.sub.5).sub. 2 N].sub.3 P+CH.sub.2                                                      1   Room                                                                               0.40                                                                              0.50                                                                              0.60                                                                              0.70                                      CHCO.sub.2 CH.sub.3     200 0.50                                                                              0.50                                                                              0.60                                                                              0.65                                                              390 0.60                                                                              0.70                                                                              1.05                                                                              1.50                                   4  [(C.sub.4 H.sub.9).sub.2 N].sub.3 P+CH.sub.2                                                       1   Room                                                                               0.40                                                                              0.40                                                                              0.50                                                                              0.60                                      CHCO.sub.2 CH.sub.3     200 0.40                                                                              0.50                                                                              0.50                                                                              0.50                                                              390 0.50                                                                              0.60                                                                              1.0                                                                               --                                     __________________________________________________________________________ 

What is claimed is:
 1. A composition comprising a major proportion of an oil of lubricating viscosity or grease prepared therefrom and a minor proportion sufficient to impart load-carrying characteristics thereto of a compound having the following general structure: ##STR10## where n is 0, 1 or 2; q is 1, 2 or 3, with the proviso that the sum of n and q equal 3 and where R and R' are each selected from alkyl of from 1 to about 32 carbon atoms, aryl, aralkyl or alkaryl of 6 to about 30 carbon atoms, alicyclic (CmH_(2m-1)) and RR' is (CH₂)_(m) comprising part of a heterocyclic system selected from pyrolidine, pryidine or piperidine and where m is from 1 to 6; R², R³ and R⁴ may be H, or alkyl of 1 to 32 carbon atoms or aryl, aralkyl, alkaryl of 6 to 30 carbon atoms, and R⁵ may be alkyl, or nitrogen-substituted alkyl of 1 to 30 carbon atoms, aryl, aralkyl or alkaryl of 6 to 30 carbon atoms.
 2. The composition of claim 1 wherein RR'N is heterocyclic moiety where RR'N is selected from ##STR11##
 3. The composition of claim 1 where the oil of lubricating viscosity is a mineral oil.
 4. The composition of claim 3 where the oil of lubricating viscosity is a synthetic oil.
 5. The composition of claim 4 where the oil of lubricating viscosity is an ester oil.
 6. The composition of claim 1 where the oil of lubricating viscosity is an oil adapted for use as a gear oil.
 7. The composition of claim 1 wherein said compound has the general structure: ##STR12##
 8. The composition of claim 7 wherein said compound is ##STR13##
 9. The composition of claim 7, wherein said compound is ##STR14##
 10. The composition of claim 7 wherein said compound is ##STR15##
 11. The composition of claim 7 wherein said compound is ##STR16##
 12. The composition of claim 4 wherein said compound has the general structure: ##STR17##
 13. The composition of claim 12 wherein said compound is ##STR18##
 14. The composition of claim 12 wherein said compound is ##STR19## 